Substrate competition and specificity at the active site of amylopullulanase from Clostridium thermohydrosulfuricum.
A highly thermostable pullulanase purified from Clostridium thermohydrosulfuricum strain 39E displayed dual activity with respect to glycosidic bond cleavage. The enzyme cleaved alpha-1,6 bonds in pullulan, while it showed alpha-1,4 activity against malto-oligosaccharides. Kinetic analysis of the purified enzyme in a system which contained both pullulan and amylose as the two competing substrates were used to distinguish the dual specificity of the enzyme from the single substrate specificity known for pullulanases and alpha-amylases.
Mathupala
S
S
Department of Biochemistry, Michigan State University, East Lansing 48824.
Saha
B C
BC
Zeikus
J G
JG
D001665:Binding Sites; D001667:Binding, Competitive; D003013:Clostridium / Q000201:enzymology*; D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007700:Kinetics; D008433:Mathematics
D006026:Glycoside Hydrolases; C100181:pullulanase